haroldhettaturbo

iTrader: (2)

Hi

My mates got a decat to fit my classic. But

Iv not seen one like it b4

Its bellmouth and split like a twin scroll but from the mouth an external pipe comes out and joins in further down.

Any ideas thanks
Dave

dnc

Difficult to tll without pics, but sounds like it is a twin-dump rather than open-kneck? I had one on previous car, Magnex IIRC. There is a separate pipe/port for the wastegate that joins up with the main pipe. Meant to smooth the gas flow by reducing the turbulance when wastegat gas meets exhaust gas.
dnc

Nemesis_911

Divorced wastegate downpipe... some of them look like that... Some have the division inside the bellmouth... Supposed to provide less turbulent exhaust flow but I've never personally experienced one myself...

joz8968

iTrader: (13)

As above, it's dedicated port for the wastegate gas flow. The idea being that it alleviates turbulence as it smoothly joins the main flow further down, and thus aids torque/power/drivability. There's a school of thought that the narrow port could be a hindrance to the w/g flapper's opening and closing action??

I had a Magnex twin port on my old 93 WRX.

I'd just go for a regular bellmouth TBH.

haroldhettaturbo

iTrader: (2)

when i get a pic i will upload it. its just cheap as chips alittle better than 170 that scoobyworld want.

haroldhettaturbo

iTrader: (2)

Specification is as our Drag Exhaust System but instead re-vents exhaust gas from the screamer pipe back into the mainpipe reducing noise levels to help comply with both track and road regulations.

thats what it is found it. screamer pipe that goes back in to the exhausts.


anyone now if there any good?

http://www.greenwoodracing.co.uk/cc_wrx_0607_stg3.asp

first pic of the down pipe is the one i have.

joz8968

iTrader: (13)

Screamer pipes are normally used with large external wastegates (i.e. a w/g remote to the turbo) - for big turbo/big power applications.

So it looks like that d/p has that extra piping to attach the free VTA end of a screamer pipe to, so that the w/g's gases get recirc'd back into the exhaust system, rather than vent to air (and therefore doing away with the "scream").

haroldhettaturbo

iTrader: (2)

so are these any good? got a vf 23 on mine. just my mates got 1 for sale and its cheep.

joz8968

iTrader: (13)

Your VF23 has an integral internal w/g... so screamer pipe/external w/g not needed.... therefore that d/p in that link not needed.

You just need to get a regular aftermarket bellmouth style d/p, a remap (with any other mods you might wnat to do)... and that's it. Job done.

haroldhettaturbo

iTrader: (2)

hi

But will it work just as well as a normal decat, with my vf23.

Mate wants 50 quid for it and 1 from scoobyworld is 170.

Thanks
Dave

joz8968

iTrader: (13)

Oops sorry, upon looking at that tiny pic of that pipe, it does look like it's a twin, divorced d/p that works as explained in the 1st few replies. I got thrown because the description mentioned "screamer pipe...".

Thereotically, it should be better, due to the two exahust streams smoothly joining together. But as said, sometimes the w/g flapper can be prevented from fully opening.

As already said, personally, I'd play safe and get a full bellmouth design, as these have no issues. Most specialists/tuners would recommend/use a bellmouth..........

You should be able to get a 2nd hand s.s bellmouth job off ebay or here for 70-80 quid if you try hard enough...